Finishing machine

ABSTRACT

A finishing machine comprises a motor mounted on a support frame and connected to a drive shaft and two or more finishing heads and an impeller fan driven by the drive shaft via a serpentine belt drive which rotates the finishing heads in opposite directions. The impeller fan impels dust from the grinding heads into a rear vacuum manifold and the support frame has rear wheels the height of which is adjustable by means of an hydraulic cylinder.

FIELD OF THE INVENTION

This invention relates to machines for finishing surfaces such asgrinders for polishing concrete floors.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 6,494,772 discloses a floor conditioning machine whichprovides a random rotating orbital action and includes a main housing,wheel assembly, a handle assembly, a motor, a belt cover, a belt, a dustrecovery system and orbital head assemblies. The belt drive utilizes aserpentine configuration which rotates head assemblies in oppositedirections so that torque is reduced and the machine is therefore easyto control and steer.

AU Patent Application 1006202204 discloses a machine which also utilizesa serpentine belt drive. A primary pulley is driven by a motor and thebelt drives pulleys which rotate head assemblies in opposite directions.However both these machines have a number of deficiencies; the dustcollection apparatus is ineffective, they are difficult to move when notin operation and changing worn belts is time consuming.

OBJECT OF THE INVENTION

It is therefore an object of the invention to provide a finishingmachine which is an improvement on the prior art machines or at leastprovides a useful alternative.

STATEMENT OF THE INVENTION

According to the present invention a finishing machine comprises a motormounted on a support frame and connected to a drive shaft and one ormore pairs of finishing heads and an impeller fan driven by the driveshaft via a serpentine belt drive which rotates pairs of finishing headsin opposite directions.

Preferably the fan impels dust from the grinding heads into a rearvacuum manifold.

Preferably the support frame has rear wheels the height of which isadjustable.

Preferably the adjustment is by means of an hydraulic cylinder.

Preferably the drive belt runs on taper lock pulleys which allow quickrelease.

Alternatively a finishing machine comprises a motor mounted on a supportframe and connected to a drive shaft which drives ten finishing headsvia a serpentine belt drive which rotates the finishing heads inopposite directions in a torque free configuration.

Preferably the finishing heads have vanes mounted on their upper side tosweep dust to vacuum ports located on the periphery of the base of themachine.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is now described by way of example onlywith reference to the accompanying drawings in which:

FIG. 1 is a side elevation of a finishing machine in use

FIG. 2 is an underneath plan view of the head assemblies of the machineof FIG. 1 and

FIG. 3 is a side elevation of FIG. 2 and

FIG. 4 illustrates an alternative configuration of grinding headassemblies.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an operator using a finishing machine which has motor1 mounted on frame 2 with removable front wheels 3 and adjustable rearwheels 4. Handles 5 have a control box 6 mounted within reach of theoperator. As well as switching the machine on and off box 6 controlsheight adjustment by operating hydraulic cylinder 7 to rotate rear wheelstrut 8 up or down. Accordingly when not in use strut 8 is lowered andthe machine can be easily wheeled to another location.

FIG. 2 shows the configuration of grinding head assemblies with a pair10 at the front corners, a pair 11 at the rear corners, one 12 in thecentre and a pair 13 between the centre and the rear corners. Theassembly 14 midway between the rear corners does not have a grindinghead but is a fan which impels dust into a vacuum manifold 15 at therear of the assemblies.

Motor 1 drives assembly 12 through a direct drive flexible coupling (notshown) and assembly 12 drives assemblies 10, 11, 13 and 14 viaserpentine belt 16. Belt 16 is so configured that it rotates pairs 10,11 and 13 and 12 and 14 in opposite directions thus tending to cancelout the torque from the grinding heads. Accordingly the machine is easyto steer since there is only minimal resultant torque.

Fan assembly 14 is optimally placed midway between the rear corners toimpel dust generated by grinding assemblies 10, 11, 12 and 13 intomanifold 15 as the machine moves forward. Manifold 15 is connected to avacuum device (not shown) mounted on the machine. This vacuuming actionis enhanced by a broom skirt (not shown) extending around the base ofthe machine.

FIG. 3 shows grinding assemblies 10, 11, 12 and 13 and serpentine belt16 driven by motor 1 which is flexibly coupled to spindle 17 of assembly12. Accordingly belt 16 is driven by pulley 18 mounted on spindle 17 andin turn drives pulleys 19, 20 and 21 mounted on spindles 22, 23 and 24of assemblies 10, 11 and 13. Spindles 17, 22, 23 and 24 are retained inbearings in plate 25 and pulleys 18, 19, 20 and 21 have a taper lock toallow quick release for fast change of belt 16.

FIG. 4 illustrates an alternative configuration of grinding headassemblies with a pair 30 at the front corners, a pair 31 at the rearcorners, one 32 at the front centre, a pair 33 on either side of andjust behind 32, one 34 between the pair 31 and a pair 35 between pair 33and pair 34.

Motor 1 drives assembly 32 through a belt and pulley coupling (notshown) and assembly 32 drives assemblies 30, 31, 33, 34 and 35 viaserpentine belt 36. Belt 36 is so configured that it rotates pairs 30,31, 33 and 35 and 32 and 34 in opposite directions, thus canceling outthe torque from the grinding heads. All assemblies have vanes (notshown) on their upper side which sweep dust to vacuum ports (not shown)on the periphery of the base of the machine.

Advantages

It will be obvious that the machine of this invention utilizes the knowntorque reduction serpentine belt configuration in a novel way to achieveoptimum dust removal with the substitution of impeller fan assembly 14in place of a grinding head or the provision of vanes on assemblies 30to 35. However It is only the ten It also provides rapid heightadjustment via hydraulic cylinder 7 to facilitate transport and rapidbelt change by means of taper lock pulleys 18, 19, 20 and 21. Electric,petrol and gas motors are available to power the grinding assemblies.

Variations

It will be realized that the foregoing has been given by way ofillustrative example only and that all other modifications andvariations as would be apparent to persons skilled in the art includingmechanical equivalents are deemed to fall within the broad scope andambit of the invention as herein set forth. Throughout the descriptionand claims of this specification the words “comprise” and variations ofthat word such as “comprises” and “comprising” are not intended toexclude other additives components integers or steps.

1. A finishing machine comprising a motor mounted on a support frame andconnected to a drive shaft and one or more pairs of finishing heads andan impeller fan driven by the drive shaft via a serpentine belt drivewhich rotates pairs of finishing heads in opposite directions.
 2. Themachine of claim 1 in which the impeller fan Impels dust from thegrinding heads into a rear vacuum manifold.
 3. The machine of claim 1 inwhich the support frame has rear wheels the height of which isadjustable.
 4. The machine of claim 3 in which the adjustment is by anhydraulic cylinder.
 5. The machine of claim 1 in which the drive beltruns on taper lock pulleys which allow quick release.
 6. A finishingmachine comprising a motor mounted on a support frame and connected to adrive shaft which drives ten finishing heads via a serpentine belt drivewhich rotates the finishing heads in opposite directions in a torquefree configuration.
 7. The finishing machine of claim 6 in which thefinishing heads have vanes mounted on their upper side to sweep dust tovacuum ports located on the periphery of the base of the machine.